The present invention relates to using Prowashonupana barley to form a food product, and the resultant Prowashonupana food products which are designed to inhibit or possibly prevent an elevated glycemic index when such products are consumed.
Dietary carbohydrates can be divided into chemically-based classifications, which include sugars, starch fractions, and non-starch polysaccharides. Certain dietary carbohydrates when consumed can result in an elevated blood sugar or glucose level, which can be indicated by a measurement known as the Glycemic Index (GI). The GI is an indication of the effect of a particular food product on a person""s blood sugar. This indication is measured by an in vivo testing procedure whereby blood samples are taken from a subject at time zero and at specific time intervals after the consumption of a food item or meal. The blood glucose level of each sample is then calculated and plotted versus the time and then the incremental area under the curve is calculated. As such, the GI will not only be calculated for the tested product but also for a reference product. The GI is expressed as a percentage based on the ratio of the mean incremental area of the test food divided by the mean incremental area for the reference food. A high GI equates to an increased blood sugar level or comparatively high blood glucose levels.
Testing a subject for GI levels can be expensive and time consuming. For this reason alternative tests have been developed which are designed to indicate the GI. One such test is known as the rapidly available glucose assay (RAG). This assay indicates the amount of glucose found in a food product available for rapid absorption into the small intestine. The test involves incubating the food with enzymes under standardized conditions. The amount of glucose that is released is then measured at different time intervals with released glucose quantitated by colorimetry or HPLC. This is then converted into an RAG measurement. There is a correlation between RAG and GI that is highly significant. The correlation of RAG to GI was discussed by Englyst et al. 1996. and Englyst et al. 1999.1,2 As such, RAG can be used as a rapid method to indicate the GI of various foods.
Elevated blood glucose will cause an elevated insulin response by the host. Increased insulin levels are known to contribute to the development of non-insulin dependent (Type II) diabetes. It has also been hypothesized that chronic consumption of a high glycemic index diet contributes to a high incidence of obesity. Food products which have a low glycemic index result in a decreased insulin response which lowers the chance of the onset of Type II diabetes. Snack foods, such as potato chips, crackers, and corn chips, as well as ready-to-eat (RTE) cereals, provide readily available starch to a consumer. This equates to a comparatively high GI. More particularly, when these products are consumed, the starch can readily be digested, which, in turn, raises the RAG or GI. Despite the undesired effect associated with consumption of such snack foods, they are popular with consumers. For this reason, it is hypothesized that despite the long term risk associated with the consumption of such products, consumers will continue to eat such food products. Thus, it is desired to have a snack food that has a desired texture and flavor but does not result in a comparatively high RAG or GI when consumed. In particular, it is desired to have a snack food comprised of an amount of grain or flour that is not comprised of readily available carbohydrates. It is most preferred if the grain or flour does not result in an elevated RAG or GI.
The GI for various foods is as follows (based on GI of glucose=100):
The source is Brand Miller3.
Generally, a GI below 55 is considered to be desirable, with lower numbers considered even better (based on GI of glucose=100).
Various known grain-based products have been analyzed to determine the GI or RAG. Prior to extrusion many of the grains demonstrate an acceptable RAG. After extrusion most the flours have a significantly higher RAG. For this reason it is desired to have a flour constituent that can be extruded and does not result in a significantly increased RAG.
Another problem is that many grain products which can be used to form a low GI snack have an undesired mouth feel and taste. Too often, such constituents are used to produce a product that is too dense and does not have a sufficient mouth-feel. Additionally, some constituents used in snack products are not nutritionally complete because they are comprised primarily of starch and contain low amounts of protein, insoluble fiber, and soluble fiber. An example of a flour product that initially has a low RAG, but is unacceptable for use is high amylose corn starch (HACS). The HACS has comparatively low protein and fiber levels; more importantly, when extruded the HACS has an elevated RAG.
Most types of barley flour have desirable protein and fiber levels but result in an elevated RAG. It is desired to have a barley flour whereby the beneficial constituents remain but the RAG is lower. Unfortunately, typical ground barleys that are extruded into a food product, provide rapidly digested starches that translate into a RAG equal to roughly 51%. It is desired to have a barley that results in an RAG that is equal to 25% or less and does not have to be specially treated.
There are some barley flours that have a lower RAG. Most of these barley flours are fractions of whole barley that have been treated to enhance the soluble fiber content. Without processing, these types of barley do not result in a lower RAG. Processing, can be expensive. It is desired to have an untreated barley that results in a low RAG and is nutritionally complete.
Prowashonupana barley is an identity preserved variety of barley having enhanced amounts of soluble and insoluble fiber. The enhanced fiber level of the Prowashonupana barley is indigenous to the Prowashonupana variety. Additionally, the Prowashonupana barley variety contains approximately half of the starch content of other types of barley. Because the Prowashonupana barley has comparatively less starch, it has been hypothesized by the inventor that it would be more difficult to form a cracker or snack. It is desired, however, to have a product that includes Prowashonupana barley, but is still considered desired by consumers. It is desired to have a product that includes the health benefits of Prowashonupana barley and still has a desired texture.
The present invention relates to a method for using Prowashonupana barley flour to form a food product and the resultant food product. The grain constituent used to form the food product can be comprised of between 50% and 100% Prowashonupana barley. A secondary grain constituent can preferably be mixed with the Prowashonupana barley to form a mixed grain product. The preferred method of the present invention involves combining an amount of Prowashonupana barley flour with an amount of another or secondary grain constituent to form a mixture of Prowashonupana barley and the secondary grain constituent known as the mixed grain product. The mixture is then extruded to form a food product.
As mentioned, the Prowashonupana barley is an identity preserved barley product having an amount of total dietary fiber equal to at least 30% by weight and an amount of protein equal to at least 16% by weight. Further, the Prowashonupana barley flour will have an amount of starch equal to about 30% by weight. As such, the Prowashonupana barley flour has comparatively higher amounts of fiber and less starch.
The food product will preferably be comprised of an amount of the mixed grain product, whereby the grain product is comprised of between 50% and 90% by weight of the Prowashonupana barley flour. More preferably, the mixed grain constituent will be comprised of between 70% and 90% by weight of the Prowashonupana barley flour, with 80% being the most preferred amount. The use of a mixed grain product is preferred to ensure that the resultant food product is not too dense. The secondary grain constituent is used to lower the density of the resultant food product.
The resultant Prowashonupana barley food product is advantageous because, when consumed, an elevated glycemic index is not contributed to and may be inhibited. Also, the food products will be nutritionally advantageous, whereby a sufficient amount of protein and fiber will comprise the food product. The resultant food product is also unique in that the RAG or glycemic index in an extruded food product will not become elevated as a result of extrusion, whereas, many other types of grains will have an elevated RAG after extrusion. Another advantage is that a snack, cracker, or ready to eat breakfast cereal can be formed from the Prowashonupana flour that has a desirable texture and mouth-feel.